Plunger-elevator accumulator.



Patented Jan. 2, I900;

G. H. REYNOLDS.

PLUNGER ELEVATOR ACCUMULATOR.

, I (Application filed Oct. 8, 1897.)

( N o M o d e l UNITED STATES PATENT OFFICE.

GEORGE H. REYNOLDS, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE CRANE ELEVATOR COMPANY, OF SAME PLACE.

PLUNGER-ELEVATOR ACCUMULATOR.

SPECIFICATION forming part of Letters Patent No. 640,589, dated January 2, 1900.

Original application filed April 30, 1897, Serial No. 684,547. Divided and this application filed October 8,1897. Serial No. 654,523. (No model.)

lowered by hydraulic pressure acting upon so as to raise said ram or plunger.

As the above type of elevator necessarily employs a plunger of considerable weight, it has been found that when traveling at a rapid speed downward sudden stoppage of such plunger produces more or less severe shock upon the car and violent strain upon the parts, the water being inelastic. It has been further found in the operation of elevators of the class referred to that when the plunger was traveling upward at a high rate of speed and the supply of motor-fluid to the cylinder was suddenly shut off there was a tendency to the creation of a partial vacuum beneath the plunger due to the great momentum of the same, and this Vacuum permitted the plunger to settle down again a short distance and caused a severe lurch of the car.

To overcome the above difficulties, Iprovide in connection with the cylinder and communicating therewith a spring-accumulator constructed to yield more or less to the pressure within the cylinder, especially sudden increases thereof, and to cause the return of a slight amount of fluid to the cylinder after any sudden closure of the operating-valve, so as to prevent the formation of the vacuum referred to beneath the elevator-ram.

Referring now to the accompanying drawings, Figure 1 represents the lower end of an elevator-cylinder and its attached operating- Valve with my improved accumulator connected to the cylinder. Fig. 2 shows the accumulator in sect-ion and on a larger scale. Fig. 3 is a top view thereof, and Fig. 4 is a plan section taken on the line 4 at of Fig. 2.

The accumulator proper comprises a cylindrical casing 5, connected to the cylinder by a port 6, having within it a plunger 7, against cylinder will be in the position shown in the drawings; but as the cylinder-pressure increases it will be raised thereby against the resistance of the springs 8, allowing some of the fluid from the cylinder to enter the casing 5 through the port 6; If the Valve con trolling the flow of fluid from the cylinder be suddenly closed, the momentum of the heavy plunger as it travels downward causes an increase of the pressure in the cylinder, and consequently an increase under the plunger 7, raising the same against the resistance of the springs 8, and thus preventing too violent or sudden stoppage of the car.

If the supply of fluid to the elevator-cylin der is suddenly cut off as the plunger is traveling upward, the momentum of its great weight causes a sudden reduction of the pressure within the casing 5, and the springs 8 be ing partially relieved of the pressure against them force the accumulator-plunger? down- Ward, pressing some of the fluid back in the elevator-cylinder to avoid the formation of a vacuum within the latter and to prevent the lurching of the car, before referred it.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is- 7 1. In a plunger-elevator, the combination with a main cylinder, of a casing communicating therewith, aplunger operating in said casing, a rod connected to said casing, and a spring interposed between said rod and plunger, and operating in opposition to the pressure in said main cylinder, as and for the purpose set forth.

2. In a plunger-elevator, the combination with the main cylinder, of a casing communicating at one end with said cylinder, a plun ger operating in said casing and projecting from the other end thereof, rods connected to said casing, and springs interposed between said rods and the projecting end of said plunger, as and for the purpose set forth.

In a plunger-elevator, a main cylinder, movement of said plunger due to increase in a casing communicating therewith, a plunger pressure in the main cylinder, as and for the operating in said casing, rods connected to purpose set forth.

said casing, and springs arranged to bear at GEORGE H. REYNOLDS. 5 one end against said rods and at the other end Witnesses:

against said plunger, the tension of said PAUL SYNNESTVEDT,

springs being exerted in opposition to the CHAS. W. HATCH. 

